You've seen the diamond shaped signs on tankers and trucks but do you know what they mean? The signs are called placards and indicate a hazard classification. A placard is a warning sign measuring 10.8 inches on each side and standing on one point (like a diamond), that is placed on the four vertical sides of the truck, rail car, intermodal container or two sides of an intermediate bulk container containing hazardous materials. Placards are required by regulatory agencies around the world when shipping hazardous materials by water, air, highway or rail.

Class 1 - Explosives
	Division 1.1 Division 1.2 Division 1.3 Division 1.4 Division 1.5 Division 1.6	Explosives with a mass explosion hazard Explosives with a projection hazard Explosives with predominantly a fire hazard Explosives with no significant blast hazard Very insensitive explosives; blasting agents Extremely insensitive detonating articles
Class 2 - Gases
	Division 2.1 Division 2.2 Division 2.3 Division 2.4	Flammable gases Non-flammable, non-toxic compressed gases Gases toxic* by inhalation Corrosive gases (Canada only)
Class 3 - Flammable Liquids
Class 4 - Flammable Solids, Spontaneously Combustible Materials, and Dangerous When Wet Materials
	Division 4.1	Flammable solids
	Division 4.2	Spontaneously combustible materials
	Division 4.3	Dangerous when wet materials
Class 5 - Oxidizers and Organic Peroxides
	Division 5.1	Oxidizers
	Division 5.2	Organic peroxides
Class 6 - Toxic* Materials and Infectious Substances
	Division 6.1 Division 6.2	Toxic* materials Infectious substances
Class 7 - Radioactive Materials
Class 8 - Corrosive Materials
Class 9 - Miscellaneous Dangerous Goods
	Division 9.1 Division 9.2 Division 9.3	Miscellaneous dangerous goods (Canada only) Environmentally hazardous substances (Canada only) Dangerous Wastes (Canada only)